1. Field of the Invention
The present invention relates to a point or near point light source for use in a projection display application, and more particularly to a xenon arc bulb having a magnetic field generated around the bulb envelope to compress the arc plasma therein.
2. Description of Related Art
Arc lamps are a type of electric-discharge lamp in which an electric current flows between two electrodes which are placed in a gas or vapor environment. The light emitted from these lamps is produced from the luminescence of the gas resulting from the increased energy state caused by the current passing therethrough. This energized gas between the electrodes is referred to as the arc plasma. A special type of arc lamp is the xenon arc lamp which typically incorporates two electrodes enclosed in a fused quartz bulb filled with xenon gas at a pressure above atmospheric pressure. The light emitted from a xenon arc bulb is substantially continuous throughout the visible spectrum and approximates daylight in color. Another advantage of xenon arc bulbs is that they are capable of producing a high intensity light. For these reasons xenon arc bulbs are used to artificially illuminate objects in light valve-based and film-based projection display systems, fiber optics networks, as well as solar simulation systems.
However, as electronics and optics have become increasingly smaller, the existing arc lamps have proven to be bulky and/or inefficient. In addition, much of the light generated by these light sources cannot be directed into or collected by the smaller components because of their size; instead it must be absorbed by the bulb or surrounding components where it generates unwanted heat. In addressing these problems a series of optical components have been employed to focus, direct and collimate the light. However, these additional components are counterproductive to the miniaturization of these systems since they add size and cost of the systems. Accordingly, there is a need to provide a smaller light source which does not sacrifice brightness or intensity.